Novel foundation pit support lattice type support changing intelligent construction control system and method

Abstract

The invention discloses a novel foundation pit support lattice type support changing intelligent construction control system and method, relates to the technical field of foundation pit support changing, and is used for automatically judging the support changing time and optimizing the support changing mode in foundation pit support construction. Longitudinal diagonal bracings, transverse diagonal bracings, splayed bracings, angle bracings and other components are arranged on the periphery of a foundation pit to form a stable lattice type supporting system, and deformation and settlement conditions of a foundation pit support structure are monitored in real time by means of arranged monitoring sensors. Dividing the support system into a plurality of grid units, and comprehensively judging the main axial direction and the secondary axial direction of each grid unit according to the wall inclination rate ratio and the support demand coefficient; then, the splayed support is alternately disassembled and reserved by combining the master-slave axial information; in the process, monitoring and verification of a closed triangular structure and a continuous oblique-lacking span are carried out on the layout of angle braces and splayed braces of the foundation pit, and the master-slave axial direction is updated through iteration so as to meet safety conditions.

Description

Technical Field

[0001] This invention relates to the field of foundation pit support and replacement technology, and more specifically, to a novel intelligent construction control system and method for foundation pit support grid-type replacement. Background Technology

[0002] With the development of information technology and automation technology, intelligent construction control systems have become an important direction for modern foundation pit support construction. By installing sensors, monitoring equipment and data acquisition systems, key data such as foundation pit deformation and support force can be obtained in real time. The system can intelligently analyze and provide feedback in real time, automatically adjust the support scheme, and ensure the safety and efficiency of the construction process.

[0003] The existing technology has the following shortcomings: Existing technologies in foundation pit support and strut replacement operations often rely on manual calculation and judgment, lacking systematic and intelligent control methods, resulting in a cumbersome construction process and significant safety risks. The fixed structure of traditional methods cannot flexibly cope with the situation and has weak adaptability.

[0004] To address the above problems, this invention proposes a solution. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, embodiments of the present invention provide a novel intelligent construction control system and method for foundation pit support grid-type replacement bracing, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A novel intelligent construction control method for grid-type foundation pit support, including the following steps; Step S1: Arrange bracing in two orthogonal directions according to the length and width of the foundation pit, denoted as longitudinal bracing and transverse bracing. Set up figure-eight bracing at the contact position between the bracing and the foundation pit. Design corner bracing at the four corners of the foundation pit to construct a grid-type support system. Obtain and calculate the horizontal displacement increment of the wall top and the settlement increment of the ground surface outside the pit. Design a dual threshold triggering mechanism to determine whether it is necessary to perform bracing replacement operation. Step S2: The smallest closed rectangular area enclosed by two adjacent transverse braces and two adjacent longitudinal braces is denoted as a grid cell. The combined master-slave coefficients of the two adjacent transverse braces and the two adjacent longitudinal braces are determined by combining the wall tilt rate ratio and the demand coefficient, and the maximum value in the longitudinal and transverse directions is taken to determine the master axis and slave axis. Step S3: Select the grid cell closest to the geometric center of the foundation pit as the initial grid. Based on the comparison of the comprehensive master-slave coefficients, determine the master axis and slave axis corresponding to the initial grid. Perform the retention or replacement operation on the figure-eight braces. For adjacent grids, the roles are reversed. First, remove the figure-eight braces along the slave axis and retain the figure-eight braces along the master axis. This process is carried out alternately, traversing all grid cells. Step S4: Monitor the corner braces and figure-eight braces for triangle closure and continuous span missing conditions. The corner braces at any of the four corners and the figure-eight braces on both sides together form a closed triangle support structure. The number of consecutive spans without figure-eight braces in any direction should not exceed the preset number of spans. If both the triangle closure condition and the continuous span missing condition are met, the brace is replaced directly. If one of them is not met, the main axis and secondary axis of the grid cell where the figure-eight brace is located are re-evaluated. After updating, the triangle closure condition and the continuous span missing condition are re-evaluated, and the maximum number of iterations is set.

[0007] In a preferred embodiment, step S1 includes the following: The grid-type support system in the foundation pit support is constructed as follows: several longitudinal braces are arranged at equal intervals along the foundation pit wall in the length direction of the foundation pit, and several transverse braces are arranged at equal intervals in the width direction of the foundation pit. The top ends of the above longitudinal and transverse braces are connected to the support structure of the foundation pit side wall, and figure-eight braces are set at the contact position between the braces and the foundation pit side wall. Diagonal corner braces are installed at the four corners of the foundation pit and connected with adjacent figure-eight braces to form a grid-type support system of corner brace-figure-eight brace combination. Acquire information on the incremental horizontal displacement of the top of the wall of the foundation pit by high-precision displacement measurement sensors installed at the top of the sidewall and at several key heights, as well as the incremental settlement of the ground surface outside the pit by settlement monitoring points deployed around the foundation pit. A dual-threshold triggering mechanism is used to determine whether the figure-eight bracing needs to be replaced. The triggering thresholds for the horizontal displacement increment at the top of the wall and the ground settlement increment outside the pit are set separately. When the detected horizontal displacement increment at the top of the wall exceeds the triggering threshold for the horizontal displacement increment at the top of the wall and the detected ground settlement increment outside the pit exceeds the triggering threshold for the ground settlement increment outside the pit, the bracing replacement operation is performed.

[0008] In a preferred embodiment, step S2 includes the following: After the dual threshold triggering mechanism determines that a support replacement operation is required, the smallest closed rectangular area enclosed between two adjacent transverse braces and two adjacent longitudinal braces in the lattice support system of the foundation pit is defined as a grid unit. Within each grid cell, two transverse braces are obtained. With the two adjacent longitudinal braces Sensors were placed at different heights on the wall to obtain data on the lateral bracing. With the two adjacent longitudinal braces The wall tilt information includes the wall top displacement increment rate and the wall bottom displacement increment rate. The average value of the wall tilt information for the same-direction bracing is used to represent the corresponding wall top displacement increment rate and wall bottom displacement increment rate. The wall tilt rate ratio for the transverse bracing and the longitudinal bracing is recorded in real time and calculated as the ratio of the corresponding wall top displacement increment rate to the wall bottom displacement increment rate. The transverse bracing wall tilt rate ratio is denoted as... The ratio of the tilt rate of the longitudinally braced wall to that of the wall is denoted as ; Simultaneously, the demand coefficients for each grid cell in the horizontal and vertical directions are calculated to measure the stress requirement of the supporting structure in that direction. The actual support stress values ​​in the corresponding directions are obtained using force sensors on the wall. The demand coefficient for each direction is calculated as the ratio of the actual support stress value to the preset allowable support stress value. The demand coefficient for the horizontal bracing is denoted as... The longitudinal support demand coefficient is denoted as ; After obtaining the wall tilt rate ratio and demand coefficient corresponding to the horizontal and vertical bracing respectively, the comprehensive master-slave coefficient is obtained by weighted summation, and weight coefficients are set. , Calculate the overall master-slave coefficient of the lateral bracing separately. Combined master-slave coefficient of longitudinal support Compare the overall master-slave coefficients of lateral bracing. Combined master-slave coefficient of longitudinal support The axis corresponding to the larger overall master-slave coefficient is designated as the master axis of the mesh cell, and vice versa.

[0009] In a preferred embodiment, step S3 includes the following: The initial grid is selected from the grid cell closest to the geometric center of the foundation pit, and the grid is determined according to the geometric distance from the center. After determining the initial mesh, the first support replacement is carried out based on the main axis and the secondary axis calculated in step S2. The figure-eight supports of the main axis are removed first, while the figure-eight supports of the secondary axis are retained. After the initial mesh is replaced, the roles of the mesh cells adjacent to the initial mesh are swapped in turn. That is, the axial bracing of the adjacent mesh cells is removed first, while the axial bracing of the main mesh is retained. The process of replacing supports begins from the initial mesh and proceeds towards the outer mesh until all mesh cells have been traversed.

[0010] In a preferred embodiment, step S4 includes the following: Monitoring and verifying the integrity of the configuration of corner braces and figure-eight braces includes the triangle closure condition and the continuous missing span restriction condition. The corner braces at any four corners and the figure-eight braces on both sides together form a closed triangular support structure, and the number of consecutive missing figure-eight braces in any direction should not exceed the preset number of spans. The specific implementation method is as follows: Triangle closure condition: The corner bracing at any four corners and the figure-eight bracing on both sides together form a closed triangular support structure. For the diagonal corner bracings set at the four corners of the foundation pit, each corner bracing and one adjacent figure-eight bracing on each side should together form a closed triangular support structure. Consecutive missing span limit: The number of consecutive missing spans in a direction should not exceed the preset span number monitoring: In any direction, i.e., longitudinal or transverse, the number of consecutive missing spans should not exceed the preset maximum allowable span number N; If both the triangle closure condition and the continuous missing span constraint condition are satisfied in the entire grid region, then the current support replacement scheme will be executed. If the monitoring finds that either the triangle closure condition or the continuous missing span constraint condition is not met, the master-slave axis calculation in step S2 is re-executed to update the determination of the master axis and slave axis. If both conditions are met after the update, no additional adjustment is needed, and all remaining replacement operations are completed according to the updated replacement plan. If the conditions are still not met, the iteration continues. Set a maximum iteration threshold M. In each iteration, re-evaluate and adjust the support replacement operation for meshes that do not meet the requirements. Then, check again whether both the triangle closure condition and the continuous missing span constraint condition are met simultaneously. If the conditions are not met simultaneously after M iterations, an alarm will be triggered.

[0011] The new intelligent construction control system for grid-type support replacement in foundation pits includes: a support system construction module, a master-slave axis judgment module, a figure-eight support replacement control module, and a support structure verification module, with signal connections between each module; The support system construction module arranges bracing in two orthogonal directions according to the length and width of the foundation pit, which are referred to as longitudinal bracing and transverse bracing. Figure-eight bracing is set at the contact position between the bracing and the foundation pit. Corner bracing is designed at the four corners of the foundation pit to construct a grid-type support system. The module obtains and calculates the horizontal displacement increment of the wall top and the settlement increment of the ground surface outside the pit. A dual threshold triggering mechanism is designed to determine whether a bracing replacement operation is required. The master-slave axis determination module defines the smallest closed rectangular area enclosed by two adjacent transverse braces and two adjacent longitudinal braces as a grid cell. It combines the wall tilt rate ratio and the demand coefficient to determine the comprehensive master-slave coefficient of two adjacent transverse braces and two adjacent longitudinal braces, and takes the maximum value in both the transverse and longitudinal directions to determine the master axis and slave axis. The figure-eight brace replacement control module selects the grid cell closest to the geometric center of the foundation pit as the initial grid. Based on the comparison of the comprehensive master-slave coefficients, it determines the master axis and slave axis corresponding to the initial grid and performs the retention or replacement operation on the figure-eight brace. For adjacent grids, the roles are reversed. First, the figure-eight brace of the slave axis is removed, and the figure-eight brace of the master axis is retained. This process is carried out alternately, traversing all grid cells. The support structure verification module monitors the triangle closure condition and continuous span missing condition for corner braces and figure-eight braces. The corner braces at any four corners and the figure-eight braces on both sides together form a closed triangle support structure, and the number of consecutive spans missing figure-eight braces in any direction should not exceed the preset number of spans. When both the triangle closure condition and the continuous span missing condition are met, the brace is replaced directly. If one of them is not met, the main axis and secondary axis of the grid cell where the figure-eight brace is located are re-evaluated. After updating, the two conditions of triangle closure condition and continuous span missing condition are re-evaluated, and the maximum number of iterations is set.

[0012] The technical effects and advantages of the novel intelligent construction control system and method for foundation pit support grid-type replacement bracing in this invention are as follows: By accurately calculating the incremental horizontal displacement of the wall top and the incremental settlement of the ground outside the pit, combined with a dual-threshold triggering mechanism, the system can automatically determine whether a support replacement operation is needed. Based on the comparison of comprehensive master-slave coefficients, it intelligently determines the master axis and slave axis of the support direction. It can dynamically adjust the support structure according to the actual changes at the construction site. Combined with the monitoring mechanism of corner braces and figure-eight braces, it can monitor each support structure in real time, ensuring the continuous stability of the support system during dynamic construction. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the intelligent construction control method for the novel grid-type support structure of the foundation pit according to the present invention.

[0014] Figure 2 A schematic diagram of multiple adjacent grid units in a lattice support system for a simplified foundation pit construction.

[0015] Figure 3 This is a schematic diagram of the intelligent construction control system module for the novel foundation pit support grid-type replacement bracing of the present invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] This invention is achieved through the collection.

[0018] Example 1: Please refer to Figure 1 As shown, this invention discloses a novel intelligent construction control method for grid-type support replacement in foundation pits, comprising the following steps: Step S1: Arrange bracing in two orthogonal directions according to the length and width of the foundation pit, denoted as longitudinal bracing and transverse bracing. Set up figure-eight bracing at the contact position between the bracing and the foundation pit. Design corner bracing at the four corners of the foundation pit to construct a grid-type support system. Obtain and calculate the horizontal displacement increment of the wall top and the settlement increment of the ground surface outside the pit. Design a dual threshold triggering mechanism to determine whether it is necessary to perform bracing replacement operation. Step S2: The smallest closed rectangular area enclosed by two adjacent transverse braces and two adjacent longitudinal braces is denoted as a grid cell. The combined master-slave coefficients of the two adjacent transverse braces and the two adjacent longitudinal braces are determined by combining the wall tilt rate ratio and the demand coefficient, and the maximum value in the longitudinal and transverse directions is taken to determine the master axis and slave axis. Step S3: Select the grid cell closest to the geometric center of the foundation pit as the initial grid. Based on the comparison of the comprehensive master-slave coefficients, determine the master axis and slave axis corresponding to the initial grid. Perform the retention or replacement operation on the figure-eight braces. For adjacent grids, the roles are reversed. First, remove the figure-eight braces along the slave axis and retain the figure-eight braces along the master axis. This process is carried out alternately, traversing all grid cells. Step S4: Monitor the corner braces and figure-eight braces for triangle closure and continuous span missing conditions. The corner braces at any of the four corners and the figure-eight braces on both sides together form a closed triangle support structure. The number of consecutive spans without figure-eight braces in any direction should not exceed the preset number of spans. If both the triangle closure condition and the continuous span missing condition are met, the brace is replaced directly. If one of them is not met, the main axis and secondary axis of the grid cell where the figure-eight brace is located are re-evaluated. After updating, the triangle closure condition and the continuous span missing condition are re-evaluated, and the maximum number of iterations is set.

[0019] In step S1, bracing is arranged in two orthogonal directions according to the length and width of the foundation pit, denoted as longitudinal bracing and transverse bracing. Figure-eight bracing is installed at the contact points between the bracing and the foundation pit. Corner bracing is designed at the four corners of the foundation pit to construct a lattice-type support system. The incremental horizontal displacement of the wall top and the incremental settlement of the ground surface outside the pit are acquired and calculated. A dual-threshold triggering mechanism is designed to determine whether bracing replacement is necessary. Specific details include: The grid-type support system in the foundation pit support is constructed as follows: several longitudinal braces are arranged at equal intervals along the foundation pit wall in the length direction of the foundation pit, and several transverse braces are arranged at equal intervals in the width direction of the foundation pit. The top ends of the above longitudinal and transverse braces are connected to the support structure of the foundation pit side wall. A figure-eight brace is set at the contact position between the brace and the foundation pit side wall to increase the overall stability of the support system. Meanwhile, diagonal corner braces are installed at the four corners of the foundation pit and connected with adjacent figure-eight braces to form a lattice support system of corner brace-figure-eight brace combination, namely a closed triangular support structure. Acquire information on the incremental horizontal displacement of the top of the wall of the foundation pit by high-precision displacement measurement sensors installed at the top of the sidewall and at several key heights, as well as the incremental settlement of the ground surface outside the pit by settlement monitoring points deployed around the foundation pit. A dual-threshold triggering mechanism is used to determine whether the support structure needs to be replaced: the horizontal displacement increment triggering threshold and the ground settlement increment triggering threshold are set respectively. When the detected horizontal displacement increment of the wall top exceeds the horizontal displacement increment triggering threshold and the detected ground settlement increment of the pit exceeds the ground settlement increment triggering threshold, the control considers the support structure to have entered a critical state and performs the support replacement operation. The dual threshold triggering mechanism significantly improves the accuracy and timeliness of support replacement timing by comprehensively considering the changes in both horizontal displacement at the top of the wall and surface settlement outside the pit, thereby optimizing the entire support maintenance process. For different construction stages, the threshold setting can be appropriately adjusted based on historical monitoring data to achieve a more sensitive or stable monitoring response. Once the triggering conditions are met, the preset support replacement strategy will be automatically invoked and the implementation operation will be executed. Through automated support replacement control, the support structure can be quickly responded to, ensuring the safety and stability of the foundation pit support system. During construction and maintenance, the working status of each sensing device and actuator will be checked regularly to ensure the reliability of the dual threshold triggering mechanism and support replacement operation, providing a temporal and spatial triggering condition basis for subsequent grid cell division and master-slave axis judgment.

[0020] In step S2, the smallest closed rectangular area enclosed by two adjacent transverse braces and two adjacent longitudinal braces is denoted as a grid cell. The combined master-slave coefficients of the two adjacent transverse braces and two adjacent longitudinal braces are determined by combining the wall tilt rate ratio and the demand coefficient. The maximum values ​​in both the transverse and longitudinal directions are used to determine the master axis and slave axis. Specific details include: The dual threshold triggering mechanism determines that a support replacement operation is required, and then performs grid cell division and master-slave axis judgment. Specifically, the smallest closed rectangular area enclosed between two adjacent transverse braces and two adjacent longitudinal braces in the grid support system of the foundation pit is defined as a grid cell. Specifically, the horizontal and vertical bracing of the foundation pit support system forms multiple intersecting grid units. The size of each grid unit is determined by the spacing between the bracing units, thus dividing the lattice support system in the foundation pit into multiple adjacent grid units. Within each grid cell, two transverse braces are obtained. With the two adjacent longitudinal braces Sensors were placed at different heights on the wall to obtain data on the lateral bracing. With the two adjacent longitudinal braces The wall tilt information includes: the wall top displacement increment rate and the wall bottom displacement increment rate. The average value of the wall tilt information for the same-direction bracing is used to represent the corresponding wall top displacement increment rate and wall bottom displacement increment rate. The ratio of the wall tilt rate for the transverse bracing and the longitudinal bracing is recorded in real time and calculated as the ratio of the corresponding wall top displacement increment rate to the wall bottom displacement increment rate. The wall tilt rate ratio for the transverse bracing is denoted as... The ratio of the tilt rate of the longitudinally braced wall to that of the wall is denoted as ; The larger the tilt rate ratio, the more obvious the tilt trend of the wall in the corresponding direction of the grid cell. In order to reduce the impact of measurement noise on the calculation results, the original displacement data can be filtered, or a sliding window can be used to smooth and average the increment rate to obtain a stable and reliable tilt rate ratio. Simultaneously, the demand coefficients for each grid cell in the horizontal and vertical directions are calculated to measure the stress requirement of the supporting structure in that direction. The actual support stress values ​​in the corresponding directions are obtained using force sensors on the wall. The demand coefficient for each direction is calculated as the ratio of the actual support stress value to the preset allowable support stress value. The demand coefficient for the horizontal bracing is denoted as... The longitudinal support demand coefficient is denoted as ; The larger the demand factor, the closer the support in that direction is to the bearing limit and the smaller the safety margin. In addition to the direct force ratio, the ratio of wall displacement to allowable displacement can also be used as a measure of the demand factor. After obtaining the wall tilt rate ratio and demand coefficient corresponding to the lateral and longitudinal bracing respectively, in order to comprehensively evaluate the support status of the lateral and longitudinal bracing, these two types of parameters are weighted and superimposed to obtain a comprehensive master-slave coefficient, and a weighting coefficient is set. , Calculate the overall master-slave coefficient of the lateral bracing separately. Combined master-slave coefficient of longitudinal support Represented as: It should be noted that the weights , Sensitivity settings can be adjusted according to project priorities, such as when stability is of greater concern. When a larger value is chosen, and more attention is paid to load requirements, the appropriate value is selected. Take the larger value; Calculated and Then, compare the sizes of the two: if If the horizontal axis is considered to be the master axis and the vertical axis to be the slave axis, then the horizontal axis is considered to be the master axis and the vertical axis to be the slave axis; otherwise, the vertical axis is considered to be the master axis and the horizontal axis to be the slave axis. It should be noted that a threshold can also be set based on the difference between the two. Each grid cell determines a main axis and a secondary axis by comparing its comprehensive coefficients in the horizontal and vertical directions. This determination process is carried out independently by each grid cell in the entire support system, and the calculation results provide a quantitative basis for the subsequent support replacement strategy.

[0021] In step S3, the grid cell closest to the geometric center of the foundation pit is selected as the initial grid. Based on the comparison of the comprehensive master-slave coefficients, the master axis and slave axis corresponding to the initial grid are determined. The figure-eight braces are retained or replaced. For adjacent grids, the roles are reversed: the figure-eight braces along the slave axis are removed first, while the figure-eight braces along the master axis are retained. This process is repeated alternately, traversing all grid cells. The specific content includes: Select the grid cell closest to the geometric center of the foundation pit as the starting point for the support replacement operation to ensure the balanced advancement of the support replacement on the surrounding grid. The initial grid is simply determined according to the grid number or the geometric distance from the center. After determining the initial mesh, the first bracing is performed based on the main axis and the secondary axis calculated in step S2: the bracing of the main axis is removed first, and the bracing of the secondary axis is retained. If the main axis of the mesh unit is transverse, the transverse bracing of the unit is removed and the longitudinal bracing is retained; otherwise, the longitudinal bracing is removed and the transverse bracing is retained. By addressing the axial bracing first, the support requirements in the main stress directions can be alleviated first, while ensuring continuous axial support. Removal can be accomplished via pre-installed movable joints, plug-and-play mechanisms, or manual control, depending on the design of the support structure.

[0022] After the initial mesh is replaced, a similar operation is performed on the mesh cells adjacent to the initial mesh. For mesh cells adjacent to the initial mesh, they share a support line with the initial mesh, so the roles should be interchanged: that is, in adjacent mesh cells, the secondary axis of the original initial mesh cell is used as the primary axis of the current mesh, and the primary axis of the original initial mesh cell is used as the secondary axis of the current mesh for the replacement operation. If the initial mesh removes the horizontal bracing, the adjacent mesh will set the vertical axis as its master axis and the horizontal axis as its slave axis; and vice versa. Subsequently, the same operation is performed on these adjacent meshes: first remove the bracing along its master axis, and retain the bracing along its slave axis. According to the above rules, the replacement can be carried out gradually from the initial grid to the outer grid in a spiral or layered manner until all grid cells are traversed. The specific advancement method can be designed as follows: first process the four neighboring grids connected to the central grid in the front, back, left, and right directions, and then expand outwards in sequence; After four neighboring grids have been processed, the process continues with four more directly adjacent grids that have not yet been processed, and then proceeds layer by layer outwards, forming an alternating support sequence from the inside out. During this process, at each new grid cell, a replacement operation is performed according to the grid's own master-slave axis determination result, and the cells are interchanged with neighboring processed grids, ensuring that adjacent grids do not continuously remove the same-direction bracing, thus maintaining the stability of the overall support system. Ultimately, the master-axis bracing of all grid cells is replaced, while the slave-axis bracing is retained sequentially, forming an orderly support replacement process.

[0023] For example: Multiple adjacent grid units in a simple lattice support system for foundation pit support, such as... Figure 2 The diagram shown is only for demonstrating the support replacement process in step S3: Figure 2 middle, Indicates horizontal direction. Indicates vertical direction, Indicates the grid number; The initial mesh is selected from the area near the center of the foundation pit, closest to the geometric center, as the starting point for the support replacement operation. For the initial grid, The grid adopts its original master-slave axis replacement support, removes the figure-eight brace of the master axis, and retains the figure-eight brace of the slave axis; , , , The four adjacent grids are swapped roles, the axial bracing is removed, and the axial bracing is retained. Continue towards the periphery , , , Advance, alternate and interchange; It should be noted that the above examples are only used to explain the support replacement process in step 3, and the actual mesh structure shall prevail.

[0024] In step S4, the corner braces and figure-eight braces are monitored for triangle closure and continuous span missing conditions. The corner braces at any of the four corners, together with the figure-eight braces on either side, form a closed triangular support structure. The number of consecutive spans lacking figure-eight braces in any direction should not exceed a preset number of spans. If both the triangle closure and continuous span missing conditions are met, the brace is directly replaced. If either condition is not met, the main axis and secondary axis of the grid cell containing the non-compliant figure-eight brace are re-evaluated. After updating, the triangle closure and continuous span missing conditions are re-evaluated, and a maximum number of iterations is set. Specific details include: Monitoring and verifying the integrity of the corner bracing and figure-eight bracing configuration includes the triangle closure condition and the continuous missing span restriction condition. The corner bracing at any of the four corners and the figure-eight bracing on both sides together form a closed triangular support structure, and the number of consecutive missing figure-eight bracings in any direction should not exceed the preset number of spans. The specific implementation method is as follows: Triangle closure condition: The corner braces at any four corners and the figure-eight braces on both sides together form a closed triangular support structure. Monitoring: For the diagonal corner braces set at the four corners of the foundation pit, each corner brace and one adjacent figure-eight brace on each side should together form a closed triangular support structure. That is, at each corner, both ends of the corner brace need to be connected to figure-eight braces in order to form a stable corner support unit. If there are missing figures on both sides of a corner, causing the corner brace and the other figure-eight brace to be unable to close and form a triangle, then the corner support structure is considered to be damaged. This damage may cause the corner brace to lose its bidirectional constraint function, so the configuration of the relevant figures on the corner brace must be re-examined.

[0025] Consecutive missing span limit: The number of consecutive missing spans in a direction should not exceed the preset span number monitoring: In any direction, i.e., longitudinal or transverse, the number of consecutive missing spans should not exceed the preset maximum allowable span number N; For example, N=2 can be set, which means that it is still acceptable if two consecutive grid units are not equipped with figure-eight bracing, but if three consecutive spans are without figure-eight bracing, it is considered a failure. This requirement ensures that there will be no excessively long unsupported sections in any direction, avoiding a significant decrease in the overall support stiffness. The specific maximum allowable number of spans N can be set by professionals in this field. During monitoring, if both the triangle closure condition and the continuous missing span constraint condition are satisfied in the entire grid area, it indicates that the integrity of the support system is well maintained, and the current round of support replacement plan can be safely executed. At this time, all remaining replacement operations are completed according to the established support replacement plan without any additional adjustments. If monitoring finds that any condition is not met, local re-judgment and iterative adjustment are required. Specifically, for the mesh cell that causes the condition to be not met, the master-slave axis calculation in step S2 is re-executed to update the determination of its master axis and slave axis. If a triangular support structure is missing at a certain corner, check the relevant mesh cells at that corner. First, recalculate the tilt rate ratio and demand coefficient for these meshes, which may change their principal axis direction. In this case, a different direction of figure-eight support will be selected for replacement in the next support replacement. Similarly, if a continuous gap in a certain direction exceeds the maximum allowable span N, re-determine the principal and secondary axes of each mesh in that direction. If necessary, adjust the support replacement direction. After the updated principal and secondary axes are determined, re-check the two conditions: the triangle closure condition and the continuous missing span constraint condition. If both conditions are met, no additional adjustment is needed. Complete all remaining replacement operations according to the updated support replacement plan. If the conditions are still not met, continue iterating. To avoid excessive iteration, a maximum iteration threshold M is set. In each iteration, meshes that do not meet the requirements are re-evaluated and the support replacement operation is adjusted. Then, the corner support triangle closure and span gap conditions are checked again. If the conditions are not met simultaneously after M iterations, an alarm or manual intervention prompt will be triggered so that engineers can conduct on-site assessment and handling. Ideally, through the above iterative verification process, all corner closed structures will eventually be restored to completeness, and the number of missing figure-eight braces in any direction will exceed the limit, thereby ensuring that the support system structure after all braces are replaced is continuous and in a safe state.

[0026] Example 2: Please refer to Figure 3 As shown, this invention discloses a novel intelligent construction control system for grid-type support replacement in foundation pits, including a support system construction module, a master-slave axis judgment module, a figure-eight support replacement control module, and a support structure verification module, with signal connections between the modules.

[0027] The support system construction module arranges bracing in two orthogonal directions according to the length and width of the foundation pit, which are referred to as longitudinal bracing and transverse bracing. Figure-eight bracing is set at the contact position between the bracing and the foundation pit. Corner bracing is designed at the four corners of the foundation pit to construct a grid-type support system. The module obtains and calculates the horizontal displacement increment of the wall top and the settlement increment of the ground surface outside the pit. A dual threshold triggering mechanism is designed to determine whether a bracing replacement operation is required. The master-slave axis determination module defines the smallest closed rectangular area enclosed by two adjacent transverse braces and two adjacent longitudinal braces as a grid cell. It combines the wall tilt rate ratio and the demand coefficient to determine the comprehensive master-slave coefficient of two adjacent transverse braces and two adjacent longitudinal braces, and takes the maximum value in both the transverse and longitudinal directions to determine the master axis and slave axis. The figure-eight brace replacement control module selects the grid cell closest to the geometric center of the foundation pit as the initial grid. Based on the comparison of the comprehensive master-slave coefficients, it determines the master axis and slave axis corresponding to the initial grid and performs the retention or replacement operation on the figure-eight brace. For adjacent grids, the roles are reversed. First, the figure-eight brace of the slave axis is removed, and the figure-eight brace of the master axis is retained. This process is carried out alternately, traversing all grid cells. The support structure verification module monitors the triangle closure condition and continuous span missing condition for corner braces and figure-eight braces. The corner braces at any four corners and the figure-eight braces on both sides together form a closed triangle support structure, and the number of consecutive spans missing figure-eight braces in any direction should not exceed the preset number of spans. When both the triangle closure condition and the continuous span missing condition are met, the brace is replaced directly. If one of them is not met, the main axis and secondary axis of the grid cell where the figure-eight brace is located are re-evaluated. After updating, the two conditions of triangle closure condition and continuous span missing condition are re-evaluated, and the maximum number of iterations is set.

[0028] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0029] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product.

[0030] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and inventive constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0031] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0032] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0033] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A novel intelligent construction control method for grid-type support structure in foundation pits, characterized by: Includes steps; Step S1: Arrange bracing in two orthogonal directions according to the length and width of the foundation pit, denoted as longitudinal bracing and transverse bracing. Set up figure-eight bracing at the contact position between the bracing and the foundation pit. Design corner bracing at the four corners of the foundation pit to construct a grid-type support system. Obtain and calculate the horizontal displacement increment of the wall top and the settlement increment of the ground surface outside the pit. Design a dual threshold triggering mechanism to determine whether it is necessary to perform bracing replacement operation. Step S2: The smallest closed rectangular area enclosed by two adjacent transverse braces and two adjacent longitudinal braces is denoted as a grid cell. The combined master-slave coefficients of the two adjacent transverse braces and the two adjacent longitudinal braces are determined by combining the wall tilt rate ratio and the demand coefficient, and the maximum value in the longitudinal and transverse directions is taken to determine the master axis and slave axis. Step S3: Select the grid cell closest to the geometric center of the foundation pit as the initial grid. Based on the comparison of the comprehensive master-slave coefficients, determine the master axis and slave axis corresponding to the initial grid. Perform the retention or replacement operation on the figure-eight braces. For adjacent grids, the roles are reversed. First, remove the figure-eight braces along the slave axis and retain the figure-eight braces along the master axis. This process is carried out alternately, traversing all grid cells. Step S4: Monitor the corner braces and figure-eight braces for triangle closure and continuous span missing conditions. The corner braces at any of the four corners and the figure-eight braces on both sides together form a closed triangle support structure. The number of consecutive spans without figure-eight braces in any direction should not exceed the preset number of spans. If both the triangle closure condition and the continuous span missing condition are met, the brace is replaced directly. If one of them is not met, the main axis and secondary axis of the grid cell where the figure-eight brace is located are re-evaluated. After updating, the triangle closure condition and the continuous span missing condition are re-evaluated, and the maximum number of iterations is set.

2. The novel intelligent construction control method for grid-type foundation pit support according to claim 1, characterized in that: The grid-type support system in the foundation pit support is constructed as follows: several longitudinal braces are arranged at equal intervals along the foundation pit wall in the length direction of the foundation pit, and several transverse braces are arranged at equal intervals in the width direction of the foundation pit. The top ends of the above longitudinal and transverse braces are connected to the support structure of the foundation pit side wall, and figure-eight braces are set at the contact position between the braces and the foundation pit side wall. Diagonal corner braces are installed at the four corners of the foundation pit and connected with adjacent figure-eight braces to form a grid-type support system of corner brace-figure-eight brace combination.

3. The novel intelligent construction control method for grid-type foundation pit support according to claim 2, characterized in that: Acquire information on the incremental horizontal displacement of the top of the wall of the foundation pit by high-precision displacement measurement sensors installed at the top of the sidewall and at several key heights, as well as the incremental settlement of the ground surface outside the pit by settlement monitoring points deployed around the foundation pit. A dual-threshold triggering mechanism is used to determine whether the figure-eight bracing needs to be replaced. The triggering thresholds for the horizontal displacement increment at the top of the wall and the ground settlement increment outside the pit are set separately. When the detected horizontal displacement increment at the top of the wall exceeds the triggering threshold for the horizontal displacement increment at the top of the wall and the detected ground settlement increment outside the pit exceeds the triggering threshold for the ground settlement increment outside the pit, the bracing replacement operation is performed.

4. The novel intelligent construction control method for grid-type foundation pit support according to claim 1, characterized in that: After the dual threshold triggering mechanism determines that a support replacement operation is required, the smallest closed rectangular area enclosed between two adjacent transverse braces and two adjacent longitudinal braces in the lattice support system of the foundation pit is defined as a grid unit.

5. The novel intelligent construction control method for grid-type foundation pit support according to claim 4, characterized in that: Within each grid cell, two transverse braces are obtained. With the two adjacent longitudinal braces Sensors were placed at different heights on the wall to obtain data on the lateral bracing. With the two adjacent longitudinal braces The wall tilt information includes the wall top displacement increment rate and the wall bottom displacement increment rate. The average value of the wall tilt information for the same-direction bracing is used to represent the corresponding wall top displacement increment rate and wall bottom displacement increment rate. The wall tilt rate ratio for the transverse bracing and the longitudinal bracing is recorded in real time and calculated as the ratio of the corresponding wall top displacement increment rate to the wall bottom displacement increment rate. The transverse bracing wall tilt rate ratio is denoted as... The ratio of the tilt rate of the longitudinally braced wall to that of the wall is denoted as ; Simultaneously, the demand coefficients for each grid cell in the horizontal and vertical directions are calculated to measure the stress requirement of the supporting structure in that direction. The actual support stress values ​​in the corresponding directions are obtained using force sensors on the wall. The demand coefficient for each direction is calculated as the ratio of the actual support stress value to the preset allowable support stress value. The demand coefficient for the horizontal bracing is denoted as... The longitudinal support demand coefficient is denoted as .

6. The novel intelligent construction control method for grid-type foundation pit support according to claim 5, characterized in that: After obtaining the wall tilt rate ratio and demand coefficient corresponding to the horizontal and vertical bracing respectively, the comprehensive master-slave coefficient is obtained by weighted summation, and weight coefficients are set. , Calculate the overall master-slave coefficient of the lateral bracing separately. Combined master-slave coefficient of longitudinal support Compare the overall master-slave coefficients of lateral bracing. Combined master-slave coefficient of longitudinal support The axis corresponding to the larger overall master-slave coefficient is designated as the master axis of the mesh cell, and vice versa.

7. The novel intelligent construction control method for grid-type foundation pit support according to claim 1, characterized in that: The initial grid is selected from the grid cell closest to the geometric center of the foundation pit, and the grid is determined according to the geometric distance from the center. After determining the initial mesh, the first support replacement is carried out based on the main axis and the secondary axis calculated in step S2. The figure-eight supports of the main axis are removed first, while the figure-eight supports of the secondary axis are retained. After the initial mesh is replaced, the roles of the mesh cells adjacent to the initial mesh are swapped in turn. That is, the axial bracing of the adjacent mesh cells is removed first, while the axial bracing of the main mesh is retained. The process of replacing supports begins from the initial mesh and proceeds towards the outer mesh until all mesh cells have been traversed.

8. The novel intelligent construction control method for grid-type foundation pit support according to claim 1, characterized in that: Monitoring and verifying the integrity of the configuration of corner braces and figure-eight braces includes the triangle closure condition and the continuous missing span restriction condition. The corner braces at any four corners and the figure-eight braces on both sides together form a closed triangular support structure, and the number of consecutive missing figure-eight braces in any direction should not exceed the preset number of spans. The specific implementation method is as follows: Triangle closure condition: The corner bracing at any four corners and the figure-eight bracing on both sides together form a closed triangular support structure. For the diagonal corner bracings set at the four corners of the foundation pit, each corner bracing and one adjacent figure-eight bracing on each side should together form a closed triangular support structure. Consecutive missing span limit: The number of consecutive missing spans in a direction should not exceed the preset span number monitoring: In any direction, i.e., longitudinal or transverse, the number of consecutive missing spans should not exceed the preset maximum allowable span number N; If both the triangle closure condition and the continuous missing span constraint condition are satisfied in the entire grid region, then the current support replacement scheme will be executed. If either the triangle closure condition or the continuous missing span constraint condition is not met, the master-slave axis calculation in step S2 is re-executed to update the determination of the master axis and slave axis. If both conditions are met after the update, no additional adjustment is needed, and all remaining replacement operations are completed according to the updated replacement plan. If the conditions are still not met, the iteration continues.

9. The novel intelligent construction control method for grid-type foundation pit support according to claim 8, characterized in that: Set a maximum iteration threshold M. In each iteration, re-evaluate and adjust the support replacement operation for meshes that do not meet the requirements. Then, check again whether both the triangle closure condition and the continuous missing span constraint condition are met simultaneously. If the conditions are not met simultaneously after M iterations, an alarm will be triggered.

10. A novel intelligent construction control system for grid-type foundation pit support, used to implement the novel intelligent construction control method for grid-type foundation pit support as described in any one of claims 1-9, characterized in that: The support system construction module arranges bracing in two orthogonal directions according to the length and width of the foundation pit, which are referred to as longitudinal bracing and transverse bracing. Figure-eight bracing is set at the contact position between the bracing and the foundation pit. Corner bracing is designed at the four corners of the foundation pit to construct a grid-type support system. The module obtains and calculates the horizontal displacement increment of the wall top and the settlement increment of the ground surface outside the pit. A dual threshold triggering mechanism is designed to determine whether a bracing replacement operation is required. The master-slave axis determination module defines the smallest closed rectangular area enclosed by two adjacent transverse braces and two adjacent longitudinal braces as a grid cell. It combines the wall tilt rate ratio and the demand coefficient to determine the comprehensive master-slave coefficient of two adjacent transverse braces and two adjacent longitudinal braces, and takes the maximum value in both the transverse and longitudinal directions to determine the master axis and slave axis. The figure-eight brace replacement control module selects the grid cell closest to the geometric center of the foundation pit as the initial grid. Based on the comparison of the comprehensive master-slave coefficients, it determines the master axis and slave axis corresponding to the initial grid and performs the retention or replacement operation on the figure-eight brace. For adjacent grids, the roles are reversed. First, the figure-eight brace of the slave axis is removed, and the figure-eight brace of the master axis is retained. This process is carried out alternately, traversing all grid cells. The support structure verification module monitors the triangle closure condition and continuous span missing condition for corner braces and figure-eight braces. The corner braces at any four corners and the figure-eight braces on both sides together form a closed triangle support structure, and the number of consecutive spans missing figure-eight braces in any direction should not exceed the preset number of spans. When both the triangle closure condition and the continuous span missing condition are met, the brace is replaced directly. If one of them is not met, the main axis and secondary axis of the grid cell where the figure-eight brace is located are re-evaluated. After updating, the two conditions of triangle closure condition and continuous span missing condition are re-evaluated, and the maximum number of iterations is set.

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